We study the convexity of the
first eigenfunction of the drifting Laplacian operator with zero Dirichlet boundary
value provided a suitable assumption to the drifting term is added. We firstly
generalize some results of N. Korevaar and S.-T. Yau to gain a Hessian estimate of
the first eigenfunction. As an application, we use this Hessian estimate to get a lower
bound of the difference of the first and second eigenvalues of the drifting Laplacian.
At the end we also find a lower bound when the Hessian estimate does not
hold.
Keywords
eigenvalue, drifting Laplacian, Hessian estimate,
fundamental gap